Shock absorber



.lune y24, 1930. R. E. xnv'fsALL' I 1,765,429

sHocK ABSRBER Filed April 9, 1927 Patented June Z4, 193() LMSALZ ROBERT E. KIMBALL, OF CLEVELAND, OHIO SHOCK ABSOB/BER Application led April 9,

This invention relates to shock absorbers of the snubber type adapted particularly for use on motor vehicles. Y

The principal object of the present invention is to provide a device of this character which improves the riding qualities of the carand which is more effective and satisfactory in operation than those employed heretofore. More particularly, it is the aim of the invention to provide a shock absorber which will snub or check sudden rebounds but which has no elfe-ct on and in fact is .functionless in ,so far as the relatively minor, and gentler relative movements are concerned between the Vcarbody andwheels.

-ll/ore specifically considerecbit is the aim of the .invention to provide a shock absorber or snubber composed yof relatively movable members connected respectively to the axle 2 0 and the chassis frame, which members are adapted to frictionally retard or check upward or rebounding movements of the car bodyfonly when such movementsreach or exceed a predetermined or given velocity or 2,5 when such movements have a given or predetermined acceleration. When the movements are relatively slow, the friction members dovnot function andin fact are substantially out of engagement.- In this manner,

v .39 wear on the friction material is reduced to a minimum and the life of the frictionmaterial isgreatly extended, this being a distinct advantage over devices of this character used at the present time wherein the friction mem bers are constantly in action and, therefore, have to be relatively frequently renewed.

'In carrying out my invention,'I provide a shock absorber or snubber composed of members-whichare connected, respectively, to the axle and chassis frame and which are con stantly moved relatively without frictionalr i927. serial NQ. 182,922.`

predetermined amount takes place so as to obtain the desired rebound checking action.

A though these results may be obtained in different ways, in the form of the invention now best known to me, the relatively movable friction members l,are brought frOm a functionless relationship which normally exists to one wherein they not only frictionally engage each other but engage under a pressure of a fixed andspredetermined amount by the effect of ,inertia on one of the members which is cause-d to move relative to another member only when upward movement of the car body is sudden enough to cause this relative movement by the effect of inertia.

The invention may be further briefly summarized as consisting of certain novel con-y structions and arrangements of parts which will be described in the `specification and s et lforth in the appended claims.

ln the accompanying sheet of drawings which illustrates the preferred embodiment of the invention:

Fig. 1 is a sectional -view showing my improved shock absorber applied to a vehicle, lthe device itself being shown partly in section and partly Vin elevation, the section being taken at right kangles to the axle; Fig. 2 is a sectional view at rightangles to the section of Fig. 1 and showing the shock absorber in elevation; andlFig. Bis a sectional view substanti ally along the lineS-S of Fig. 1.

Referring now'to the drawings, 10 represents one ofthe sidemembers of the chassis frame, 11 is `anaxle which ma be a rear axle and 12 isa leaf spring o the car or vehicle. l y

In the embodiment illustrated, the parts connected lto the chassis `frame include two bars orstraps 13 and 14 kwhich are arranged side by side 1and areadapted to move vertically or in an endwise direction between two strips offriction material 15-and16 support ed by a box-like memberl or casing 17 suitably connected with the axle. Inthis instance, the box or casing 17 is pivotally connected to a forlr18, see Fig. 3, secured to a strap 19 attachedl to a bracket 2O secured tothe under side ofthe spring 12 by U-bolts 21 extending about the axle housing as indicated in Figs.

1 and 2. Any other suitable means for making the mechanical connection, however, may be employed.

rllhe strips 15 and 16 of friction material which may be brake lining material are secured, respectively, to theback wall 17a of the box 17 and to a wall 17b which is engaged by a stiff spring herein shown as a coil spring 22 arranged between the wall 171 and the front wall 17C of the box. The wall 17b carries a bolt shank 23 which extends through the spring and through the front wall 17c of the box and has its outer end threaded to accommodate a pair of nuts 24 which ca-n be adjusted to varv the position of the friction inember 16 w1 n reference to the opposing fric-l tion member 15 with spring 22 of a given size provided to cause a predetermined frictional engagement on the straps 13 and 14. There will be no occasion to adjust the nuts 24 except to compensate for wear on the friction members 15 and 16. Referring now to the straps 13 and 14, the strap 13 at all times pai-taires of the up and down movement of the chassis frame but this strap is preferably pivotally connected to the chassis frame and this is accomplished, in this instance, by securing Yit by rivets or otherwise to the flat face of a pintle 25 journaled in a pair of bearing members 26 attached to a member 27 which, in turn, forms a part ofor is secured to thechassis frame. 1n the embodiment illustrated, this supporting member 27 is in the form of an angle which is adaptedto extend between and be secured to the side members of the chassis frame. Y

rllhe other strap 14 is supported by the strap 13 but yieldingly supported from it and in this instance, the upper end of strap 14 which is bent laterally, as at 14a is supported on the lower end of a bolt 28 which passes freely 'through the upper laterally bent end 13'L1 of strap 13, there being between the upper end of the bolt 28 and the laterally bent end 13a of strap 13 a relatively weak spring 29. That is to say, strap 14 is supported from strap 13 through spring 29 and when in its normal position with reference to strap 13 the straps are a minimum distance apart, this distance being such that the straps and friction members 15 and 16 may move relatively7 up and down without vfrictional resistance. 1t iff-.fill be observed, however, that the adjacent sides of the straps 13 and 14 are provided with complementary wedge pieces 13b and 14") and when strap 14 is at its normal position with reference to strap 13, the wedge pieces permit the two straps to occupy the relatively narrow space which permits the free movement referred to above relative to the friction members.

The straps 13 and 14 occupy the relative positions described above and shown in Fig. 1 of the drawings not only when the car is stationary but while it is in motion provided the rate of speed or the condition of the roadway does not result in a rebouliding` or upward motion of the car body at more than a predetermined rate or with more than a predetermined acceleration. Thus though m the car body and axle may move relatively up and down, there is normally no snubbing action to this movement and, therefore, no Wear on the friction members. n

However, when the control Vof the upward movement of the car body is needed as when a sudden rebound occurs, the shock absorber becomes immediately effective to frictionally retard the rebound and this is accomplished by a relative lengthwise movement of the straps 13 and 14Ydue to 'the inertia of the spring supported strap 14 resulting in the straps being wedged apart suliiciently to bring them into frictional engagement with the friction members 15 and and as soon as this occurs, strap 14 is pulled down by the downward drag exerted on it by friction member 16, the downward movementbeing limited by a suitable stop which, in this instance, is in the form of a pin or-stud 30 carried by one of the straps and projecting into a slot 31 of the other strap, the length of the slot being such as to permit just the desired separation of the st laps. rlhis results in a definite ctional resistance being exerted by the friction members 15 and 16 on the straps and this is directly proportional to the strength of the spring 22 which is made strong enough to give the desired snubbing action.

rlfhe velocity or acceleration the upward movement of the car body vwhich is necessary to cause relative lengthwise movement of the straps 13 and 14 to result in the frictional engagement with the friction members' 15 and 16 as explained above-in other words, the suddenness of the upward movement of the car body which will allow strap 14 by its in ertia to tend to remain stationary so as to bring the wedges into action will depend upon the strength of spring 29 which is so selected as is also thevstrength of spring 22 to produce the desired snubbing action when the same is needed for easy riding.

1t is desirable, if not necessary, that the iis two straps 13 and 14 be normally held in their 'j relatively narrow or contracted relationship to prevent rz ttlingand possible drag by the 1 friction member 16 on the strap 14. rlhis is accomplished in this instance by two lugs 13c and .14E attached to the contiguous faces of the straps 13 and 14 and having overlapping inclined ends reversely tapered with respectl to the wedges 13b and 14h, the eect of the overlapping inclined ends of the lugs being to normally hold the straps the minimum distance apart so that they may move freely between the friction members 15 and 16.

Vhen a sudden rebound occurs, due to the elfect of inertia on strap 14, the straps are moved relatively and wedged apart and thereby caused to be brought into acer-tain frictional engagement with .I the friction members 15 and 16. This immediately causes friction member 16 to exert a drag on strap 14 ythereby causing the ywedges' to separate the straps the maximumamount (determined by the length of the slot 31), resulting in the maximum frictional engagement` between the straps and the friction members under the full pressure of spring 22. VOn thereversal of movement between the axle and chassis following the sudden rebound referred to, the lugs 13c and 14C again function to restore and hold the straps in their narrow or contracted relationship until a rebound of suf- (icient acceleration again occurs to bring the shock absorber into action in the manner explained above.

Not only are the' riding qualities yof the car improvedby reason of the fact that the snubber is effective to check the upward movement of the car body when the snubbing action is desired, but it will be seen that at no time is the snubber brought into act-ion by a downward movement of the axle relative to the car body or chassis frame as is the case with all snubbers or shock absorbers of the friction type at present in use. Thejfact that the axle may move downward relative height with Ireference to the ground over which t-he car is passing.

While I have shown one embodiment of the invention which, in practice, has provento be effective and which illustrates the principle'of the invention, the construction may` be varied in details and other ways of carrying out the principle may occur to one skilled in the art-and I, therefore, do not desire to be confined to the details or arrangements shown but aim in my claims to cover all modifications which do not involve a departure from the spirit and scope of the invention.

Having thus described my invention, what l claim is: t

1. In a shock absorber, a pair of relatively movable friction members adapted to be connected respectively to the axle and chassis frame of a Vehicle, and means responsive to a relative movement of a predetermined acceleration or greater between said members of the vehicle for causing said friction members to frictionaliy resist such movement by a definite resistance. Y

2. In a shock absorber for checking the rebound between two relatively movable parts, a pair of friction members normally inactive for relative movement of any ampliinde between said parts and having means responsive to the movement of one'of said parts in a given direction and of a predetervmined acceleration or greater to cause fricrebounds between two relatively movable parts, a pair of fric-tionmembers, and spring means for causing said members to frictionally engage under predetermined pressure, said spring means being rendered effective on the occurrence of a relative movement of said parts of a predetermined acceleration.

d. in 'a shock absorber for checking sudden rebounds betweenv two relatively movable parts, a. pair of friction members, and spring means for causing said members to frictionally engage under predetermined. pressure, said spring inea-ns being normally ineffective and being rendered effective by the effect of inertia on one of the parts of "the shock absorber when relative movement of a given acceleration and in a given direction occurs between said parts. l

5. in a shock absorber for checking the rebound between two relatively movable parts, friction means connected to one of said parts, friction means connected to the other 'of said parts, said friction means bebetweenisaid two friction means when a rep bound movement of predetermined acceleration or greater occurs between said parts.

in a, shock absorberfor checking sudden lrebound between twoA parts, two sets of friction members, one connected to one of said parts and one to the other, said friction members being normally freely relatively movable, and a spring adapted under certain conditions to cause said friction members to frictionally engage each other, one of said sets comprising parts relatively movable by the effect of inertia on the occurrence of a movement of given acceleration to permit the spring to act. i 'A i 7. ln a shock absorber for checking sudden rebound between two parts, two relatively movable friction means adapted to be connected respectively to said relatively movable part-s and'normally freely movable relatively, a spring for causing frictional engagement between said means, one of said friction means being composed of two members, one supported so that it may move relaiis ian

tive to the other by the effect-of inertiatherey,

on thereby serving to cause the friction 8. In a shock absorber for checking sud-v den rebound between two relatively movable parts, friction means connected to one of said pa-rts and friction means connected to the other of said parts, the friction means being normally freely relatively movable, a normally inactive spring for causing predetermined pressure between the two friction means, lone of said friction means compriso ing two members relatively movable in an endwise direction by the effect of inertia acting on one of them when a sudden rebound occurs between said relatively movable parts to cause said spring to act.

9. In a shock absorber for checking sudden rebound between two relatively movable parts, two pairs of friction members, one pair being connected to one of said parts and the other pair being connected to the other of said parts and one pair being movable between the other pair, the members of one pair being relatively movable by the effect of inertiai on one of them when a sudden rebound occurs, so as to vary the effective width thereof, and a spring for pressing the friction members together, said spring being rendered effective on the occurrence of said relative movement.

10. In a shock absorber for checking sudden rebound between two relatively movable parts, a pair of friction members connected to One of said parts, a second pair of friction members connected to the other of said parts and normally movable freely between the first pair, said second pair of friction members being relatively movable and one being yieldingly supported so that by the effect of inertia'thereon said two members will move relatively on the occurrence of a rebound of predetermined acceleration, andv a spring which is normally inactive and which is rendered effective to press the friction members together under predetermined pressure on the occurrence of said relative movement.

1l. In a shock absorber for checking sudden rebound between two relatively movable parts comprising a friction member connected to one of said parts and a two-part member connected to the other, one of said parts being yieldingly, supported so that it may move relative to the other by the effect of inertia thereon and said yieldingly supported part being normally movable close 'to but freely relative to the'friction member, a normally inactive spring adapted to press the members together, said yieldingly supported member when moved Arelative to the companion member by the effect of inertia being brought in contact with the friction member and by the latter moved to a position relative to the companion member, such that it is engaged by the friction member under the full pressure of the spring.

12. A shock absorber for checking sudden rebounds between two relatively movable parts comprisinga friction member connected to one of the parts and a two-part member connected to the other, and a normally inactive spring associated with the lfriction member, one' of the parts of said two-part member being normally freely movable close to kthe friction member and by the effect of inertia thereon onthe occurrence of a 4su'dden'rebound being VAspread from` 'the companion member and moved into friotional` 'Contact with the friction member and by lthe latter being still further spread from the companion member soas toenable the friction member to engagethe same under lthe full pressiire 1 of the spring.

13. A shock absorber' for checking sudden rebounds between two relatively movable parts comprising a friction member connected to one of 'said parts anda two-part Vthereby cause them to be further wedged apart to'cause frictional engagement with :the friction me v`,ber under the full pressurehof the spring. i

n testimony whereof, hereuntoV afx my signature.

` ROBERT E. KIMBeLr. 

